Two PhD scholarships in Mobilisation of Phosphorus from Waste Materials by Microorganisms

Two PhD positions at Department of Chemical and Biochemical Engineering (DTU Chemical Engineering, Campus Roskilde) are available within a new project (MiCroP) funded by The Danish Council for Strategic Research. MiCroP aims at using microbial inoculants as efficient biofertilizers to mobilize phosphorus from soil, rock, and untreated or gasified organic waste. The project consortium involves partners from DTU-KT, KU-Science, Novozymes, Knowledge Center for Agriculture, and international partners from Australia, Germany, Switzerland and Sweden.

Phosphorus (P) is an essential nutrient and limits plant growth in many soils. Since global commercially available P stocks will eventually become scarce and phosphate production costs are likely to increase, novel agricultural approaches to secure sustainable plant P nutrition are urgently needed. These should address the fertilizer value of recycled wastes and ensure a more efficient crop use of P. Recently, microbial biofertilizers based on phosphate solubilizing microorganisms (PSM) have been marketed to improve plant P nutrition, but the underlying mechanisms are poorly understood.

We hypothesize that the performance of biofertilizers can be improved by a deeper knowledge of P solubilization mechanisms, and by exploiting synergies between various microorganisms including arbuscular mycorrhizal fungi (AMF). Furthermore, we expect that biofertilizer technologies can be utilized to enhance plant access to P from waste streams. This approach would enable sustainable P-use in food and feed production, and thereby have a great impact on agriculture and food prices, also in a global perspective.

The two PhD projects focus on plant utilization of P in bioashes, as well as the effect of PSM and AMF and their expected synergies in plant P-access. The bioashes rich in plant nutrients result from low-temperature gasification of waste materials, a technology that provides bioenergy with high efficiency and simultaneously hygienizes the waste. It is hypothesized that the bioash can eventually be used as matrix for commercial formulations of biofertilizer products.

Responsibilities and tasks

PhD project 1 will focus on molecular and plant physiological aspects of uptake of inorganic bioash-P, assisted by PSM and AMF biofertilizers. The work will target:

Identification of optimal nutrient conditions for the PSM to solubilize bioash-P,

Clarification of molecular mechanisms underlying PSM activity

Description of plant P-uptake of bioash-P using radioisotopes

Determination of the persistence of PSM/ash/AMF combinations in soil under controlled plant growth conditions

PhD project 2 will focus on the biofertilizer performance and persistence, affected by PSM strain, ash type, AMF, crop, and soil conditions. Specific biofertilizer products will be developed including formulations for the commercial market. The work will target:

Identification of optimal PSM/ash/AMF/crop combinations and major constraints to PSM performance

Development of an effective formulation of suitable PSM

Field trials to test the performance and persistence of different formulations under natural plant growth conditions

The two PhD projects will be managed to ensure a high degree of collaboration and synergy. Furthermore, there will be strong interactions with other researchers in the consortium, including secondments at CSIRO (Australia) and SLU (Sweden), respectively.

We seek two energetic and skilled candidates. The successful applicants will be highly motivated and will have demonstrated the ability to work independently. It is a plus if you have experience and interest in one or more of the following research areas:

PhD1: plant molecular biology, microbiology and plant physiology

PhD2: soil chemistry and biology, plant nutrition

Qualifications
Candidates should have a master’s degree in engineering, plant biology, agronomy or a similar degree with an academic level equivalent to the master’s degree.

Approval and Enrolment
The scholarships for the PhD degree are subject to academic approval, and the candidates will be enrolled in one of the general degree programmes of DTU. For information about the general requirements for enrolment and the general planning of the scholarship studies, please see the DTU PhD Guide.

We offer
We offer an interesting and challenging job in an international environment focusing on education, research, public-sector consultancy and innovation, which contribute to enhancing the economy and improving social welfare. We strive for academic excellence, collegial respect and freedom tempered by responsibility. The Technical University of Denmark (DTU) is a leading technical university in northern Europe and benchmarks with the best universities in the world.

Salary and appointment terms
The salary and appointment terms are consistent with the current rules for PhD degree students. The period of employment is 3 years.

Applications must be submitted as one PDF file containing all materials to be given consideration. To apply, please open the link « Apply online, » fill in the online application form, and attach all your materials in English in one PDF file. In the field “Please indicate which position(s) you would like to apply for” please indicate which project you are applying for.

The file must include:

A letter motivating the application (cover letter)

Curriculum vitae

Grade transcripts and BSc/MSc diploma

Excel sheet with translation of grades to the Danish grading system (see guidelines and excel spreadsheet here)

Candidates may apply prior to ob­tai­ning their master’s degree, but cannot begin before having received it.

DTU Chemical Engineerings main activities lie within the areas of product design, process design and production in the chemical, biotechnological, pharmaceutical, food technological and energy technological industries. The ECO Center for Ecosystems and Environmental Sustainability conducts research to supply knowledge and data needed by companies and society to evaluate the sustainability of products, technologies and processes.

DTU is a technical university providing internationally leading research, education, innovation and public service. Our staff of 5,000 advance science and technology to create innovative solutions that meet the demands of society; and our 9,000 students are educated to address the technological challenges of the future. DTU is an independent academic university collaborating globally with business, industry, government, and public agencies.